package com.yitianyigexiangfa.coap.cbor.util;

/**
 * @author Bill Lau
 * @date 2017-12-22
 */
public class ConvertUtil {

    public static String bytesToHex(byte[] bytes) {
        char[] hexArray = "0123456789ABCDEF".toCharArray();
        char[] hexChars = new char[bytes.length * 2];
        for (int j = 0; j < bytes.length; j++) {
            int v = bytes[j] & 0xFF;
            hexChars[j * 2] = hexArray[v >>> 4];
            hexChars[j * 2 + 1] = hexArray[v & 0x0F];
        }
        return new String(hexChars);
    }

    public static byte[] hexStringToBytes(String hexString) {
        if (hexString == null || hexString.equals("")) {
            return null;
        }
        hexString = hexString.toUpperCase();
        int length = hexString.length() / 2;
        char[] hexChars = hexString.toCharArray();
        byte[] d = new byte[length];
        for (int i = 0; i < length; i++) {
            int pos = i * 2;
            d[i] = (byte) (charToByte(hexChars[pos]) << 4 | charToByte(hexChars[pos + 1]));

        }
        return d;
    }

    private static byte charToByte(char c) {
        return (byte) "0123456789ABCDEF".indexOf(c);
    }


    public static String string2Unicode(String string) {
        StringBuffer unicode = new StringBuffer();
        for (int i = 0; i < string.length(); i++) {
            char c = string.charAt(i);
            unicode.append("\\u" + Integer.toHexString(c));
        }
        return unicode.toString();
    }

    public static String unicode2String(String unicode) {
        StringBuffer string = new StringBuffer();
        String[] hex = unicode.split("\\\\u");
        for (int i = 1; i < hex.length; i++) {
            int data = Integer.parseInt(hex[i], 16);
            string.append((char) data);
        }
        return string.toString();
    }

}
